On this label
- USPS Ground Advantage: 2-5 days, tracking and $100 insurance included; prices start at $8.40 at a Post Office.
- Boxes over 1 cubic foot may be charged by dimensional weight: length x width x height ÷ 139.
- With no stated shipping time, the FTC rule expects you to ship within 30 days.
For a small seller, shipping is both a cost and a promise. The cost is the label and the box. The promise is the delivery time on your listing, and federal law expects you to keep it. Getting both right starts with knowing the main postal options and how they price a package.
The two USPS workhorses
| USPS Ground Advantage | Priority Mail | |
|---|---|---|
| Delivery time | 2-5 days | 2-3 days |
| Tracking | Included | Included |
| Insurance | $100 included; up to $5,000 more can be purchased | Up to $100 with most shipments |
| Starting price at a Post Office | $8.40 | $11.50 |
| Pricing basis | Weight and zone; under 1 lb priced at 4, 8, 12 and 15.999 oz tiers | Weight and zone, or Flat Rate boxes up to 70 lbs |
| Size limit | 130 inches combined length and girth | 108 inches combined length and girth |
USPS notes that shipping online with Click-N-Ship gets lower commercial rates than the Post Office counter prices above, and businesses can opt into a business rate card. The maximum weight for any USPS package is 70 pounds.
Light items: Ground Advantage under a pound
Ground Advantage is the Postal Service’s best-priced service for items up to 15.999 ounces, priced in steps at 4, 8, 12 and 15.999 ounces and by distance. For jewelry, stickers, small accessories and other light goods, weighing each product with its packaging and keeping under the next step is a reliable way to save money. Packages over 15.999 ounces are charged by the pound, rounded up.
Tip: Weigh a fully packed sample of every product, including tissue, insert cards and tape, and record it in your listing notes. Guessing weight is how small sellers lose a dollar on every order.
Big, light boxes: dimensional weight
For packages larger than 1 cubic foot (1,728 cubic inches), USPS may charge by dimensional weight instead of actual weight. Multiply length by width by height in inches and divide by 139 to get the dimensional weight in pounds. A 14 × 12 × 12 inch box is 2,016 cubic inches, which gives a dimensional weight of about 14.5 pounds, even if the pillow inside weighs two. Ground Advantage also lists a $21.00 added fee for packages over 2 cubic feet.
The fix is simple: use the smallest box that protects the item. For soft goods, a padded or poly mailer often avoids dimensional pricing altogether.
Flat Rate: when weight is high and distance is far
Priority Mail Flat Rate boxes and envelopes ship anywhere in the United States for the same price up to 70 pounds, and the boxes are free from USPS. They suit heavy, dense items going a long way. If you use a free Priority Mail box, you must pay for Priority Mail service, and Flat Rate packaging must close within its normal folds.
Items with restrictions
USPS separates prohibited items, which cannot be mailed at all, from restricted items, which can be mailed only under certain conditions. Lithium batteries are a common example for small sellers: new batteries installed in small electronics are usually acceptable, but used ones may only travel by ground transport. Ground Advantage is USPS’s primary option for hazardous materials that can only go by ground. Check the Postal Service’s list of domestic shipping prohibitions and restrictions before listing anything with batteries, aerosols, fragrances or flammable materials.
Packing that protects the item and the margin
- Choose packaging by product, not by habit: mailers for soft goods, small boxes for fragile items.
- Leave space for cushioning on all sides of fragile items; nothing should rattle when you shake the box.
- Seal seams fully and remove or cover old labels and barcodes on reused boxes.
- Put a packing slip and a return address inside in case the outside label is damaged.
Your shipping promise is a legal promise
The Federal Trade Commission’s Mail, Internet, or Telephone Order Merchandise Rule applies to most goods ordered online. When you advertise a shipping time, you must have a reasonable basis for it. If you state no time, you must have a reasonable basis to believe you can ship within 30 days, which is why the rule is often called the 30-day rule. If you learn you cannot ship on time, you must seek the customer’s consent to the delay, and the notice must tell them they can cancel for a full, prompt refund. If you decide you can never ship, you must cancel promptly and refund in full.
For handmade and made-to-order products, that makes realistic processing times essential. A listing that says “ships in 1-3 days” when the item takes a week to make sets you up for both complaints and a rule violation.
Fees on shipping charges
Marketplace fees often apply to shipping too. Etsy’s 6.5% transaction fee applies to the shipping you charge, and Amazon’s referral fee is calculated on the total price including shipping. See Marketplace Fees Compared: What Etsy, Amazon and a Shopify Store Take From a $40 Sale for the numbers, and Handling Returns and Reviews: Platform Policies, FTC Rules and Replies That Help for return shipping, which on Amazon is handled through prepaid labels for US sellers.